BACKGROUND The epidemiology identifies cyclic lumbar loading as a risk factor for cumulative trauma disorder. Experimental biomechanical and physiological confirmation is lacking. The objective of this study was to asses the impact of different rest durations applied between periods of cyclic loading on the development of an acute lumbar disorder which, if continued to be subjected to loading, ...

Title of Document: A NON-LINEAR DAMAGE MODEL WITH LOAD DEPENDENT EXPONENTS FOR SOLDERS UNDER SEQUENTIAL CYCLIC SHEAR LOADS Elviz George, Ph.D., 2015 Directed By: Professor Michael G. Pecht, Department of Mechanical Engineering The damage state of a material subject to cyclic loads is often characterized by the cycle ratio of applied cycles to the number of survivable cycles. The damage in a mat...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoplasticity model. The results of the thermo-mechani...

The paper represents a test investigation of the mechanical properties and acoustic emission (AE) characteristics low-strength coal specimens subjected to cyclic loading unloading. From lab tests, following conclusions can be obtained: (1) axial strain is very well linear with loading–unloading cycle number, circumferential volumetric strains are approximately quadratic functions number; (2) Un...

Abstract This work investigates the quasi-static, low-cycle and fatigue behavior of hybrid glass/ultra-high modulus carbon (GC) low modulus/ /high (CC) fiber composites. These pseudo-ductile unidirectional interlayer hybrids are a new type composites whose potential is not yet fully understood, particularly under cyclic/fatigue loading. Different test methods (digital image correlation, video e...

objectives : microbial leakage through the implant-abutment (i-a) interface results in bacterial colonization in two-piece implants. the aim of this study was to compare microleakage rates in three types of replace abutments namely snappy, goldadapt, and customized ceramic using radiotracing. materials and methods: three groups, one for each abutment type, of five implants and one positive and ...

in the present investigation, the cyclic load deformation behaviour of soil-fly ash layered system isstudied using different intensities of failure load (i = 25%, 50% and 75%) with varying number of cycles (n =10, 50 and 100). an attempt has been made to establish the use of fly ash as a fill material for embankments ofhighways and railways and to examine the effect of cyclic loading on the lay...

Age-related decline in periosteal adaptation negatively impacts the ability to utilize exercise to enhance bone mass and strength in the elderly. We recently observed that in senescent animals subject to cyclically applied loading, supplementation with Cyclosporin A (CsA) substantially enhanced the periosteal bone formation rates to levels observed in young animals. We therefore speculated that...

Rock structures are subjected to cyclic tension-compression loading due to a blasting, earthquake, traffic and injection-production in underground storage case. Therefore study the fatigue behavior of rock samples under this type of loading is required. In this study, the accumulated fatigue damage for a Green Onyx rock sample which consisted of only one mineral composition with two-step high-l...